Rui Maciel <rui.mac...@gmail.com> writes: > class AbstractVisitor(object): > def visit(self, element): > pass
A small improvement to your code: If you want an abstract method – that is, a method which should not be called directly but which sub-classes should over-ride – then your abstract method should not ‘pass’. Instead, it should ‘raise NotImplementedError’ so this will be clear to anyone if the MRO falls back to the abstract method. > not_a_valid_type = "foo" > > model.accept(not_a_valid_type) At this point, the ‘not_a_valid_type’ object is asked for its ‘visit’ method, and a TypeError is raised. That's good, because it informs the person looking at the code that this object doesn't support the needed behaviour. This is as it's meant to be; what problem are you pointing out here? -- \ “Software patents provide one more means of controlling access | `\ to information. They are the tool of choice for the internet | _o__) highwayman.” —Anthony Taylor | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
